Pneumatic abrading cushion



.March 18 19.24.

A. W. MALL PNEUMATIC ABRADING CUSHION Fi1ed Dec. 12 1922 Patented Mar. 18, 1924.

PAgTENT OFFICE.

ARTHUR WILLIAM MALL, F MILWAUKEE, WISCONSIN.

PNEUMATIC ABRADING CUSHION.

Application filed December 12, 1922. Serial No. 606,480.

T 0 all whom t may concern.:

Be it known that I, ARTHUR WILLIAM MALL, a citizen of the United States, and resident of Milwaukee, in the county of Milwaukee and State of Wisconsin, have invented certain new and useful Improvements in Pneumatic Abrading Cushions; and I do hereby declare that the following is a full, clear, and exact description thereof.

The invention relates to rotary pneumatic abrading cushions. It comprises an endless outer casing terminating at yielding square side edges, the casing covering an inner tube, means being provided for securing the inner tube and the casing to a rotary shaft.

Hitherto difficulty has been experienced with abrading cushions by reason of the fact that it has been necessary to provide rigid members at the side. These are apt to come in contact with the objects worked on and cause damage thereto.

It is an object of the present invention to avoid this diiiculty by so constructing the inner tube and the casing that they will yield at the edges and consequently will not indent or otherwise mar the articles being subjected to abrasion. The entire outer face of the casing is useful for abrading purposes.

An object of the invention is the makin of the edges of the outer casing sharp and square. This facilitates the abrading operation and promotes neatness of work, the sharp edges being adapted to be inserted into corners and grooves. Thus the cushion is useful with objects of various shapes.

With the above and other objects in view f which will appear as the description proceeds, the invention resides in thel novel construction, combination and arrangement of parts substantially as hereinafter, described and more particularly defined by the apdr Disk has a central opening therein,`

and is provided with a directed sleeve 11 at the opening, adapted to receive a shaft for rotating the disk. Spaced inwardly slightly from the outer edge of the disk, is an integral cylindrical iange 12, concentric with, and extending in the same direction as sleeve 11. Adjacent flange 12 is a lip 13 formed integral with the disk. An inner tube 14 is provided enveloping flange 12, and in supericial contact therewith throughout a large ai'ea. The flange is provided with an opening for the reception of valve 15 for the'inner tube, which is secured in position by means of nut 16.

A casing is provided for the inner tube. It has an annular bead 17, having a relatively wide contact with the smooth surface of flange 12. The bead fits snugly into tlie concave surface 18 of lip 13. The casing fits closely on the outer surface of the lip and extends to the plane of the surface of disk 10 to whence it is outwardly directed, its surface lying'in this plane. It extends outward for a short distance, and is then extended sharply laterally at 19 forming a sleeve supporting portion 20 which is bowed slightly when inner tube 14 is inflated, from ange 12. The corner formed at 19 is sharp and square.

The sleeve supporting portion is directed inwardly at 21'for a short distance, the casing having a surface lying in the plane of a retaining ring 22 which is provided with a lip 23 similar to lip 13. The casing terminates in a bead 24 similar to bead 17, but

fitting on a pair of sharp annular teeth 25 which are spaced slightly apart, and which cooperate with the lip 23 to retain the bead securely in position. The ring being maintained tightly against the edge of the fiange by means of spaced screws 26.

The inflation of inner tube 14 tends to move the beads of the casing apart, consequently, the pointed lips 13 and 23 extending towards each other, exercise an 'effective gripping'action on the bead and secure the casing tightly in position. The casing may be made of canvas, or of rubber, or may be constructed in any manner in which the ordinary tire casing is constructed. Applicant does not limit himself to a casing made of any particular kind of material. A sand papersleeve 27 is fitted over the sleeve supporting portion 20 of the casing, and terminates at points 19 and 21. t

The structure provides a, soft `cushion adapted to withstand long usa e and eective to prevent leakage of air. t will be observed that the outermost portions of disk and ring 22 are spaced yinwardly from sleeve 27. Consequently the entire surface of the sleeve may be used for polishing. There is no danger of indenting or otherwise marring the sur aces brought in contact with the sleeve. As the corners formed at 19 and 21 are sharp, the cushion may be used for operating in corners and grooves.

Claims:

1. In a pneumatic polishing wheel, the combination of a rigid cylindrical member, means for securing said member to a shaft, an inner tube about said member, a casing about said inner tube, means securin said casing to said member, said casing ing adapted to carry a sleeve, the edges of said casing overhanging said cylindrical member to provide freely yieldable edges.

2. A pneumatic olishing wheel comprising a cylindrical ody portion having in- Leemans wardly directed flanges, a casin having outwardly directed flanges adapte to interlock with said inwardly directed flanges, an inne'r tube within said casing, said casing overhanging said anges, and an outerabrasive sheet covering the peripheral portion of said casing.

3. A pneumatic polishing wheel comprising a cylindrical body portion having inwardly directed flanges, one of said dan es being detachable, a casing having outwar 1 directed flanges adapted to interlock with said inwardly directed flanges, an inner tube within said casing, said casing overhanging said iianges, and an outer D abrasive sheet covering the peripheral portion of said cas- 111 n testimony that I claim the foregoing I havehereunto set my hand at Milwaukee in the c ounty of Milwaukee and State of Wisconsm.

ARTHUR WILLIAM MALL. 

